Uplink physical channels of Long Term Evolution (LTE) system include a Physical Random Access Channel (PRACH), a Physical Uplink Shared Channel (PUSCH), and a Physical Uplink Control Channel (PUCCH). The uplink of the LTE adopts the single-carrier Orthogonal Frequency Division Multiplexing (OFDM) technique, and the reference signal and the data are multiplexed together by means of Time Division Multiplexing (TDM).
While downlink physical channels of the LTE include a Physical Downlink Shared Channel (PDSCH), a Physical Downlink Control Channel (PDCCH), a Physical Broadcast Channel (PBCH), a Physical Multicast Channel (PMCH), a Physical Control Format Indicator Channel (PCFICH), a Physical Hybrid ARQ Indicator Channel (PHICH), and an Enhanced Physical Downlink Control Channel (EPDCCH).
In the LTE system, uplink control information and downlink control information are transmitted by the PUCCH and PDCCH respectively. Wherein the PUCCH is used to transmit the uplink control information (UCI) including a Scheduling Request (SR), a positive acknowledgement/negative acknowledgement (HARQ-ACK/NACK) of the Physical Downlink Shared Channel (PDSCH) and Channel State Information (CSI) fed back by a UE. Wherein the CSI further includes three forms: a Channel Quality Indication (CQI), a Precoding Matrix Indicator (PMI) and a Rank Indication (RI). There are two ways to transmit the CSI: a periodic CSI and an aperiodic CSI, wherein after an eNB has configured the periodic CSI through a high-layer signaling, a UE transmits the CSI at a certain time interval in the fixed ways, while the aperiodic CSI is that the eNB triggers the aperiodic CSI through DCI, the UE transmits the CSI after receiving the DCI.
The PDCCH is configured to transmit Downlink Control Information (DCI), the DCI is mainly used to schedule the PDSCH and the PUSCH, and after receiving the DCI, the UE receives the PDSCH transmitted by an Evolved-NodeB (eNB) according to the DCI indication or transmits the PUSCH to eNB according to the DCI indication. Resource block assignment information, a Modulation and coding scheme (MCS), a Downlink Assignment Index (DAI), a Channel State Information request, Cyclic shift for DM RS and OCC index and Transport Block Size (TBS), etc. are mainly included in the DCI, and after receiving the above described DCI, the UE receives the PDSCH transmitted by the eNB or transmits the PUSCH to the eNB according to the DCI indication.
The above described TBS represents the size of the transport block. In order to improve the system frequency spectrum efficiency, the Multiple-Input Multiple-Output (MIMO) technique is introduced in the LTE system, and multiple-antenna units are adopted at both transmitting end and receiving end in a wireless system, which takes advantage of the rich spatial multi-dimensional characteristic of the wireless scattering channel and works by means of multiple-transmitting ends and multiple-receiving ends to achieve the effect of improving the system channel capacity. After the MIMO is introduced, each carrier can support the multiplexing transmission of a plurality of Transport Blocks (TB), and the eNB needs to inform the TBS of each TB to the UE.
When the DCI schedules the UE to transmit an uplink subframe, the DAI is referred to as UL DAI which represents the number of the ACKs required to be fed back in the uplink subframe to be transmitted by the UE; and when the DCI schedules the UE to receive a downlink subframe, the DAI is referred to as DL DAL which represents that which order of the current subframe is in downlink subframes scheduled in a scheduling window.
The related LTE system includes two kinds of scheduling which are dynamic scheduling and semi-persistance scheduling (SPS), wherein the dynamic scheduling is that the eNB schedules the UE according to related communication requirements, that is, the eNB transmits one DCI, the UE receives one PDSCH or transmits one PUSCH according to the current DCI; and the semi-persistance scheduling (SPS) is that the eNB activates the SPS through the DCI, and after the SPS is activated, the UE receives the PDSCH or transmits the PUSCH at the fixed interval without being informed by the eNB using the DCI, until the eNB uses the DCI to activate the SPS, but in related LTE standards, the maximum MCS limit for the SPS scheduling is 15.
In the LTE protocol of Release 9 (Rel-9), the downlink Single user Multiple-Input Multiple-Output (SU-MIMO) technique is introduced in order to improve the system frequency spectrum efficiency, and in the related LTE protocol, the number of transmission antennas for the eNB is up to 8, and the number of the transport blocks in transmission is up to 2, while in LTE protocol of Release 10 (Rel-10), the uplink SU-MIMO is introduced, and in the related LTE protocol, the number of the uplink transmission antennas for the UE is up to 4, and transport blocks in uplink transmission is up to 2.
In the LTE standard, a base station can schedule transmission of 2 transport blocks in one subframe through one DCI, and an MCS, a New Data Indicator (NDI) and a Redundancy version (RV) of the 2 scheduled transport blocks can be indicated respectively.
In the related technique, when transmitting a plurality of transport blocks, the transmitting end uses different precoding to perform coding and modulation for the different transport blocks, which, to certain extent, causes the reduced system performance of the transmitting end and the receiving end, and cannot meet the requirements.